There is disclosed in U.K. Patent No. 2091313 a method of underpinning structures using piles of relatively small diameter. This method has proved to be particularly successful but in certain circumstances the support provided by the piles requires augmentation. Such circumstances arise where a cavity appears beneath and around the foundation or footing of the building to be supported.
In the past, to support structures exhibiting this problem, it has been necessary to excavate down to a level beneath the bottom of the footing so that grout or concrete can be introduced into the cavity. For a domestic dwelling this is often inconvenient and expensive, and excavation work causes considerable disruption and mess.
It is an object of the present invention to obviate or mitigate these disadvantages.